Effect of selective laser melting process parameters of SS 310 on relative density, surface roughness, and microstructure at different volumetric energy density

The selective laser melting (SLM) process is one type of additive manufacturing (AM) that has gained significant traction in the industry for producing metal alloys as it offers increased geometric flexibility. AM's considerable benefit is its ability to create lightweight, durable, and intricate forms. The study used a design of experiment (DOE) to examine the impact of process parameters like laser power, scanning speed, hatch spacing, and layer thickness on the relative density, surface roughness, and microstructure of SS 310 austenitic stainless steel, evaluating the samples using volumetric energy density (VED). The microstructure analysis revealed that despite the energy density, all samples exhibited columnar grains oriented toward the build. However, the varying energy densities significantly influenced the grain's size. The phase analysis of the samples has been examined by the X-ray diffraction method. The materials analyzed were produced within the VED range of 74.67-178.57 J/mm3, and many characterization techniques were employed for investigation. The findings indicate that a significantly high density of 99.65% and suitable surface roughness Ra of 7.027 mu m can be achieved with a VED of 113.63 J/mm3 and 103.57 J/mm3, respectively. The optimal parameters for density and surface roughness have been determined in this study.